The process of removing the permanent magnetization of a ferromagnetic object, so that the residual flux density is zero, under conditions of a zero H field is called demagnetization or deperming.
There are two principle methods that may be used in demagnetizing ferromagnetic objects. They are: (1) the application of a negative coercive force to the object being demagnetized and (2) demagnetization by reversals.
In the first method, the magnetic flux density B can be reduced to zero by the application a coercive force H.sub.c. However, upon removing this field, the residual flux density will rise to some value greater than zero. Although it may be possible to completely demagnetize the object by increasing H slightly more than the coercive force, this process requires an accurate determination of B and H and the hysteresis loop.
The second and more popular method of demagnetizing is called demagnetization or deperming by reversals. In this method, on each reversal, H is brought to a smaller maximum amplitude, so that the object is eventually left in a state of complete demagnetization.
Although such a demagnetization procedure can be completely carried out in a matter of seconds with small objects, several minutes may be required for each reversal for large objects because of the slow decay of the induced eddy currents and the reluctance of the domains to change polarity.
U.S. Pat. No. 4,867,108, granted Sep. 19, 1989, to L. L. Forde, et al, teaches of an electrostatic power system for increasing the performance of an internal combustion engine.
U.S. Pat. No. 4,856,482, granted Aug. 15, 1989, to E. Linder, et al, discloses a method of controlling the demagnetizing phase of electromagnetic devices, particularly of electromagnetic valves in internal combustion engines.
U.S. Pat. No. 4,388,666, granted Jun. 14, 1983, to A. Kuno, et al, discloses a demagnetizer for removing the residual magnetism in an entire stationary automotive vehicle.
U.S. Pat. No. 4,378,581, granted Mar. 29, 1983, to A. Kuno, discloses demagnetizing apparatus for removing the residual magnetism in the body of an automobile. Its purpose is to remove the magnetic field distortion in a bearing indicator.
U.S. Pat. No. 4,213,428, granted Jul. 22, 1980, to P. Bradley, discloses electromagnetic augmentation for an internal combustion engine to increase the engine efficiency by magnetically guiding the piston. Magnetic forces are used to attract and repel the piston in synchronization with its normal motion.
U.S. Pat. No. 4,158,346, granted Jun. 19, 1979, to C. G. Roberts, et al, teaches of an apparatus to improve the automotive efficiency of an internal combustion engine by using a set of inductive coils connected to the battery terminal of the vehicle
U.S. Pat. No. 4,074,670, granted Feb. 21, 1978, to C. G. Roberts, et al, discloses apparatus for improving the efficiency of an automotive vehicle by using a pair of closely adjacent electrically conductive coils.
U.S. Pat. No. 1,424,140, granted Jul. 25, 1922, to J. B. Replogle, discloses a magnetic throttle positioner that minimizes the effect of hysteresis to maintain accurate throttle positioning.
Several of the referenced prior art disclose methods and apparatus for demagnetizing an entire vehicle, while others disclose demagnetization of various components within the structure of an automotive vehicle. Also, some of the above referenced prior art disclose methods of demagnetizing automotive accessories to improve engine performance.
Therefore, there is a particular need for a demagnetization system as applied to an internal combustion engine of an automotive vehicle to reduce or minimize engine drag, which when implemented, can result in improved engine efficiency and performance.